Digital pens of various kinds are known. Generally they incorporate a small camera located adjacent to the nib and which observes the writing made using the pen and stores a digital record of it. For this to have full relevance it is vital that the pen knows where on the page the writing is being made.
If the pen uses Anoto® Functionality, developed by Anoto AB, then the writing must be made onto special paper which is printed with a proprietary pattern of dots which enables the pen to identify the location very accurately. Pens using this functionality are available from a number of manufacturers, including Logitech's “io” pen and Sony-Ericsson's “Chatpen CHA-30”. The paper bearing the proprietary pattern is also available from a number of sources in a variety of forms, such as Oxford's Easybook®, Franklin Covey's “iScribe”, Esselte's memo notebook and 3M's Post-It® notes.
Digital pens are also available, from Seiko, which are used in combination with a device which is clipped to the page being written onto, the clip incorporating two infra red sensors which enable it to identify where the pen is relative to the device clipped to the page. Such pens can be used with ordinary plain paper.
A schematic of a prior art digital pen 10, of the kind which uses Anoto® functionality, is provided in FIG. 1. It includes an ink cartridge 11 with nib 12 for conventional writing, a miniature camera 13 adjacent the nib 12 for observing the writing being made, a processor 14, a read/write memory 15, a battery 16 and a communications unit 17. The camera 13 observes the use made of the pen 10 on the proprietary paper and a digital record of the use made of the pen 10 is processed by the processor 14 stored in the memory 15. The digital record includes what was written or drawn by the pen and where on the pattern of dots on the proprietary paper it was made.
Many prior art digital pens (including Anoto® pens) also include a real time clock 18 in order that the times when it is used can be recorded as part of the digital record of the use. Many also include a unique, unmodifiable identifier (ID) which is “burned in” to memory at the time of manufacture, and which is also included in the digital record of the use made of the pen, such that the source of the digital record can always be identified.
Once the digital information is stored in the digital pen it can be used for a wide, indeed almost infinite, variety of uses. At its simplest it can be downloaded to a computer for long term storage or to control the computer. It can also be used in combination with a mobile phone to, for examples, send a text message to another mobile phone, to send a fax, or to link to the Internet. Transfer of the data from the digital pen to other devices may be via wired connections but is more conveniently wireless, using any appropriate technique such as infra red or Bluetooth.
An aim of the present invention is to provide a new form of digital pen which provides new functionality and opportunities to exploit the technology described above.